My favourite interview with John Lennon was by “whispering” Bob Harris in 1975. Throughout, Harris is the opposite of incisive, but his warm, respectful, almost innocent presence seems to relax Lennon into being unusually open and collusive; sure, the acerbic wit and that compulsive self-awareness are there as always, but in the last few seconds, Lennon dissolves with playful delight into a character halfway between Peter Cook and Peter Sellers. I mention this because Lennon is the protagonist of Kevin Barry’s second novel, and one of the many pleasures of Beatlebone was that it sent me back into my own past relationship with Lennon and, as Barry has it, “all the sweet and thorny emotions he routinely sprang in his brilliant and nerveless song-writing”.

The Lennon of Beatlebone is 37. The story opens as he arrives by night and incognito on the west coast of Ireland in May 1978; “all he asks” is to “spend three days alone on his island”. The island in question is Dorinish in Clew Bay, County Mayo, which the real‑life Lennon bought in 1967 at “the knock‑down price of £1,550” – and which he briefly visited with his first wife, Cynthia, and then with Yoko Ono. Barry’s Lennon has returned nine years later in search of solitude and in order to “scream his fucking lungs out” and “at last to be over himself”.

Screaming therapy is something Lennon began in 1970 after reading The Primal Scream by the American psychiatrist Dr Arthur Janov. At its simplest, the idea was that neurosis is best treated by summoning up the repressed trauma of childhood and comprehensively re-experiencing it in order to release the otherwise stored toxicity. Lennon never finished the course but some of the results can be heard on the 1970 album John Lennon/Plastic Ono Band. So we’re several years on when we meet Barry’s fictional Lennon being driven “fast and west” from the airport by the superbly drawn Cornelius O’Grady, a somewhat Mephistophelean character who will lead Lennon through a series of misadventures as bad weather and press avoidance require that they delay their trip to Dorinish Island.

But the bones of the plot are not at all what this novel is about. Rather, it is a psychological exploration of “love, blood, fate, death, sex, the void, mother, father, cunt and prick” set against a beautifully rendered backdrop of turbulent skies, seas, hills and west-of-Ireland weather. It is also a darkly wry novel with lots of Beatle references for those who (like me) experience an adolescent leap of joy whenever they pop up: there is no Gideon’s Bible at the first hotel; O’Grady’s hair is “greased and fixed like a ducktail joint”; Lennon is “so tired, he hasn’t slept a wink”.

Barry won the Impac Dublin prize with his first novel, City of Bohane, and here again, sentence by sentence, the writing is original, exact and telling. When Lennon is forced to lie low at the Amethyst Hotel on nearby Achill Island, the hog-like man running a “ranting” cult there has “tiny yellowish piss-hole-in-the-snow-type eyes” while his young acolyte has “milk-bottle shoulders”. There are a dozen great passages that lyrically solder the profound to the profane in the way of the great Irish playwrights. And lines emerge every few pages that make you want to read them again: the “sea-rasp outside hoarse as love by night whispered”; “dead love stories are what make us”.

But for all this, on the macro level, the novel didn’t quite work for me. The problem manifests itself in the uneasy fissure between Barry’s command of language and his Lennon’s less comfortable relationship to words: “What’s the fucking word? Crepescular.” (Is that “e” meant to be a Liverpudlian pronunciation?) This bum note proved symptomatic of a deeper issue which, I think, is to do with the artistic difficulty of inhabiting and portraying Lennon’s deep consciousness. It is notoriously hard to fictionalise public figures, especially linguistic artists; and for me the real Lennon kept hijacking the fiction and seizing back the biography of both the inner and outer life. Beneath everything else, the fictional spell must bind and the real-life Lennon simply wouldn’t let the Barry-Lennon convince me of his reality.

The novel also felt too fractured, as if compiled from distractions rather than written through: there are lots of short, bitty paragraphs – often in single lines, which then run the risk of making the blank space between them seem melodramatic. In part six, Barry makes the structural mistake of dropping in almost 30 pages in which a new narrator writes about his journeys around Clew Bay and how he came up with the idea for the book. “The idea is that I would get to the Island and I would Scream … ” The reader has to presume that this is Barry himself. But the effect of this disclosure on me was further to dispel the fiction by colonising the Barry-Lennon from the other direction – so that as well as the external pressure from the real Lennon, the Barry-Lennon began to feel hollowed out from the inside, as if some kind of proxy for autobiographical memoir.

All of which is to say that while I thoroughly enjoyed Beatlebone, somehow the sum was slightly less than its many fine and savoursome parts.

• Edward Docx’s The Devil’s Garden is published by Picador. To order a copy of Beatlebone for £10.39 (RRP £12.99), go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min. p&p of £1.99.